Paper-pulp screen



N0. 611,90l. Patented Oct. 4, I898. E. W. GOODBICK.

PAPER PULP SCREEN.

(Application filed Aug. 10, 1897.)

3 Sheets-Sheet I.

(No Model.)

N0. 6l|,90l. Patented Oct. 4, I898. E. -W. GUUDBICK'.

PAPER PULP SCREEN.

(Application filed Aug. 10, 1897.)

3 Sheets-Sheet 2.

(No Model.)

5 Show Wow. 16 J witnesses GE u N0. 6ll,90l. Patented Oct. 4, I898. E.W. GOODRIGK.

PAPER PULP SCREEN.

(Application filed Aug. 10, 1897.)

(No Model.) 3 Sheets$heet 3.

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NITED STATES PATENT rrrcn.

EDWARD W. GOODRICK, OF APPLETON, WISOONSIN.

PAPER-PU LP SCREEN.

SPECIFICATION forming part of Letters Patent No. 611,901, dated October4, 1898.

Application filed August 10, 1897, Serial No. 647,760. (No model.)

To all whom it may concern.-

Be it known that I, EDWARD W. GOODRICK, a citizen of the United States,residing at Appleton, in the county of Outagamie and State of Wisconsin,have invented certain new and useful Improvements in Paper-Pulp Screensand I do declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use the same, reference being hadto the accompanying drawings, and to the figures of reference markedthereon, which'form a part of this specification.

Heretofore'it has been common to construct pulp-screens of flat orcylindrical plates provided with meshes of various shapes. In suchscreens the meshes soon become enlarged by wear, thereby necessitatingthe removal of the plates and substituting new ones. These plates whenplaced in position remain stationary and an agitator is employed tocreate the necessary back action for the purpose of keeping the meshesclear. It has been found in practice that strings and lumps accumulateon the discharge side of the screen. These lumps and strings are asourceof great annoyance, because they have to be constantly removedassoon as they form in order to maintain the efficiency of the screen.The stationary screen-plates frequently become loose and get out ofplace and much attention is required in inserting new screws andfastening them in place. This constant readjustment injures the woodworkto which the plates are fastened and is 'very objectionable.

The object of my invention isto overcome these and other defects in thescreens now in common use. This I do by employing a centrifugal screenwherein the centrifugal force causes the pulp to flow outwardly andcirculate over the interior of the screen and pass more rapidly throughthe meshes. This screen is composed of sections adapted to be adjustedso as to regulate the size of the meshes of the screen to compensate forwear. In connection with this centrifugal screen is employed an agitatorfor creating the necessary back action in the pulp to keep thescreenmeshes clear. These, together with certain other peculiar featuresand combinations of parts constituting the difierent characteristics ofmyinvention, will be more fully described hereinafter and pointed out inthe claims.

- In the accompanying drawings, Figure 1 represents a vertical sectionof myinvention on the line 1 1 of Fig. 2; Fig. 2, a plan, partly insection, on line 2 2 of Fig. 1; Fig. 3, a horizontal section through theline 3 3 of Fig. 1; Fig. 4, a detail view of one of the series of ringswhich compose the cylindrical screen; Fig. 5, a vertical section of thescreen, in which the rings and their associated parts are shownenlarged; Fig. 6, an enlarged detail sectional view of a portion of theseries of rings, showing the manner in which they are separated throughthe line y y of Fig. 7; Fig. 7, a top View, partially in section,showing a portion 'ofa ring, a separating-block, and a rib within whichone side of the block is seated. Fig. 8 is a perspective view of one ofthe separating-blocks. Fig. 9 is a perspective View of the screen andits casing, in which'parts are cut away, and arrows desig nate thedirection in which the pulp flows; and Fig. 10, a side elevation, partlycut away.

I Reference-numeral 1 represents a circular vat in which the screeningmechanism is located. This mechanism consists of a vertical cylindricalscreen 2, keyed to a vertical driveshaft 3, which latter is providedwith a horizontal pulley 4. The lower end of this shaft revolves in abearing 5 in the bottom of the vat, while the upper portion of the shaftrevolves in a bearing 6 in a cross-bar 7. The screen 2 is surrounded byan outer cylindrical casing 8, having a larger diameter than the screenin order to leave vertical chambers 9, into which the pulp passes onleaving the screen. These chambers are separated from each other by aseries of radial ribs 10, which extend from the top down to near thebottom of the screen, being closed at the top by a capplate 11, securedto the vat and not connected to the revoluble screen. They are open atthe bottom in order to communicate with horizontal chambers 27 and theducts of the centrifugal agitator 12, located in the bottom of thecylinder. At intervals the ribs lOare prolonged down to the bottom ofthe horizontal chambers 27 to form end walls 10, which close theopposite ends of the chamber and divide the vertical chambers intogroups for a purpose to be presently described.

13 represents an annular flange extending across from the inside of thevat to the outside of the cylindrical casing 8 to form an overflowtroughfor the reception of dirt and other refuse matter.

The screen is composed of a series of rings 14, placed one upon theother and spaced apart to form the desired meshes 15 by removable blocks16. These blocks are arranged in horizontal rows between the rings andare retained in position and separated from each other by being seatedin sockets 17 in the edges of the ribs 10. The rings are T- shaped incross-section in order to form a horizontal flange 18, which rests uponthe intervening block 16, and a vertical flange 19,Which projects overthe vertical face of the block a sufficient distance to leave thedesired opening or mesh 15 between it and the flange or edge of theadjoining ring. Hence it will be seen that when the meshes becomeenlarged by wear the rings can be removed and thinner blockssubstituted. When a sufficient number of rings have been placed inposition to make a cylinder of the required height, the cap-plate 11 isplaced over the top ring and screwed down, thereby binding all the ringsin position.

The reaction or pulsating movement is obtained in the cylinder-chambers9 for the purpose of keeping the meshes of the screen clear by means ofa centrifugal agitator revolving with and having an axis common to thescreen and constituting a part of the centrifugal cylinder. Thisagitator consists of a bottom plate 25, provided with a plurality oftangential ducts 21, receiving at their inner ends 25 and discharging attheir outer ends 26 into the horizontal chambers 27 common to a group ofthe vertical chambers 9, whence it flows upward or downward, as will nowbe explained. The discharge is interrupted and made intermittent tocreate upward back pressure by means of a circular series of segmentalcut-ofis 22, with intervening open recesses 23. In the present instancethree outoffs and three recesses are shown. When the ends 26 of theducts 21 come in front of one of these cut-ofis 22, the outward flow ismomentarily stopped and the inertia of the fluid creates a back pressureand action in the two cylinder-chambers 9 above the horizontal chamber27 and between end walls 10, as denoted by upgoing arrows. This backaction arrests and diverts the outflow of stock like that produced in ahydraulic ram, opening the meshes and driving the refuse matter awayfrom the inside surface of the cylinder. This refuse matter, beingdriven back, will rise to the top of the cylinder.

The construction of my device having been set forth, I will now describeits operation, arrows denoting the flow of the pulp. A sufficientquantity of fluid pulp is introduced .chine.

into the top of the revoluble screen to raise the level to that of thegate 31 at the side, after which the screen is made to revolve. Thebottom of the screen being closed, the only escape of the pulp isthrough the meshes in the vertical side. The centrifugal force createdby the revolution of the screen makes the pulp leave the middle of thescreen and climb up the inside, as represented by dotted lines 30 inFig. 1, thereby urging the pulp outward through the meshes into thevertical chambers 9, whence it flows by gravity downward into the commonhorizontal chambers 27, outward through discharge-openings 29, thenceinto the intervening recesses 23 to the large chamber 32 below, and fromthe latter it flows outward into any suitable reservoir. The lowerportion of the screen being immersed in the pulp whichhas passed throughthe screen, the pulp is sucked up into the ducts 21 of the agitator andforced outwardly into the horizontal chambers 27, from which it flowsdownward back into the subchamber 32, momentarily rising when the outerends of the ducts are closed by the cut-cits, as heretofore described.\Vhen additional unscreened pulp is introduced into the top of thescreen, it will make the screened pulp overflow the gate 31 and pass outof the ma- Thus cycles of intermittent currents are kept flowing in thevat while the screening takes place. After having been screened thestock passes from the centrifugal cylinder intermittently into the vatbetween the cut-ofls 22, whence it flows out of the vat through theflow-box 24, as indicated by arrows.

The centrifugal action on the stock is such that it will keep chips andextraneous matter from going to the cylinder by means of theirdifference in specific gravity, the heavier matter going through themeshes and the lighter climbing to the top, where it can be readilyremoved by an attendant without stopping the continuous action of themachine. The rotary action of the cylindrical screen also keeps thestock in constant circulation without being stirred by an attendant.

Having thus described myinvention, what I claim as new, and desire tosecure by Letters Patent, is-

1. In a pulp-strainer, a revoluble screen, and a centrifugal agitatorbelow said screen, provided with outwardly-extending ducts in andthrough which the pulp is received and discharged, in combination withdevices for intermittently closing the ducts to produce a pulsatingmovement in the pulp, substantially as described.

2. In a pulp-strainer, the combination of a centrifugal pulp-screencasing, a screen in said casing, a centrifugal agitator and means forproducing an intermittent discharge from the agitator,

3. In a pulp-strainer, a pulp-screen casing, a centrifugal agitatorprovided with ducts and having a vertical axis, and devices for IIOgiving the ducts an intermittent discharge, in combination with avertical cylindrical screen discharging outwardly, substantially asdescribed.

4. In a pulp-strainer, a pulp-screen, a centrifugal agitator providedwith curved ducts, in combination with cut-off devices spaced apart andlocated around the line of travel of the discharge ends of the ducts ofthe agitator to check intermittently the flow of the pulp from theducts, substantially as described.

5. In a pulp-strainer, a centrifugal screen, in combination with acentrifugal agitator, substantially as described.

6. In a pulp-strainer, a centrifugal screen, in combination with acentrifugal agitator and means'for producing an intermittent dischargetherefrom, substantially as described.

7. In a pulp-strainer, avat and a centrifugal screen having a verticalaxis, located in the vat, in combination with devices for causing anintermittent backfiow through the meshes of the screen, substantially asdescribed.

8. A-cylindrical pulp-screen composed of disconnected rings T'-shaped incross-section, and blocks interposed between the outer flanges of therings.

9. In a pulp-strainer, the combination with a centrifugal screen, of acasing connected thereto and provided with surrounding vertical chambersinto which the screen discharges, and an agitator arranged and adaptedto create backflow in said chambers, and hence through the meshes of thescreen.

In witness whereof I affix my signature in presence of two witnesses.

EDWARD W.

Witnesses:

R. G. DU BoIs, R. S. WARFIELD.

GOODRIOK.

